The market of Metropolitan Optical Networks (or metro networks which are optical networks spanning distances up to several hundred kilometers, typically serving large, concentrated metropolitan areas, interconnecting a full-range of client protocols from enterprise/private customers in access networks to backbone service provider networks) is becoming the largest transport segment of high-speed interconnection in current and future Optical Networks. During the last years, the network's topologies and structures have been experiencing a paradigm shift in such a way that the ultra-high speeds links occurs mostly within Metro distances.
Unlike earlier topologies (where the high speed links were mainly in ultra-long haul networks between the network hubs) in the Metropolitan Optical Networks, the links' speed were reduced, as in a classical tree hierarchy. The main drivers of the recent changes come from the content delivery evolution and data centers topologies, which effectively generate the lion's share of high speed interconnection within metro distances. This includes, for example, interconnection between the cities and the data center “warehouses” that are usually located external to the city centers, in the range of up to 40 miles.
As a result, there is a need for Metro-focused solutions in the speed of 100 G and above. The major parameters that define this Metro segment are price, power and performance. However, the priorities between these three parameters, and the actual parameters values, are significant and unique to the Metro segment. In addition to spectral efficiency, high Optical Signal To Noise Ratio (OSNR) sensitivity, and full compensation for the linear channel distortions (e.g., Chromatic Dispersion—CD and Polarization Mode Dispersion—PMD), low power consumption and low cost is very critical in the metro segment. Without achieving low cost and low power consumption, the move to high quantities of 100 G coherent links will be delayed and the whole market will be pushed away in time.
The power consumption levels should meet the relevant modules form factors, which mostly should be pluggable. A 100 G C Form-Factor Pluggable (CFP—a multi-source agreement to produce a common form-factor for the transmission of high-speed digital signals) is the leading desired one, targeting sub 24 W of total power consumption, allowing sub-15 W of power consumption for a coherent-metro ASIC. Consequently, the ability to support the “coherent metro ASIC” requires very extensive VLSI implementation capabilities and optimizations of the Digital Signal Processing (DSP) coherent algorithms.
It is therefore an object of the present invention to provide a method and system for providing MIMO equalization for baud rate clock recovery in coherent DP-QPSK metro systems, using coherent DSP for 1 sample/symbol.
It is another object of the present invention to provide a method and system for providing MIMO equalization for baud rate clock recovery in coherent DP-QPSK metro systems with reduced processing complexity, which allows using optoelectronic components with reduced BW, lower sampling rate and less power consumption.
Other objects and advantages of the invention will become apparent as the description proceeds.